Actinic 03 Blue - 100% blue actinic 03 phosphor that peaks at 420 nanometersThe Actinic 03 Blue provides light in the 420 nanometer range that reflects color pigments in organisms such as corals, fish and invertebrates causing them to fluoresce glowing colors. Its spectrum resembles that of the absorption peak of chlorophyll-a, which is the most important pigment found in plant cells. Replacement compact fluorescent lamps for BioCube Aquarium Systems